1. Field of the Invention:
The present invention is directed to a prosthetic device, and more specifically to a prosthetic substitute for the condyle of the mandible. A synthetic prosthetic meniscus is also used with the prosthetic condyle.
2. Description of the Prior Art:
The mandible or jaw bone is the largest and strongest bone in the face and provides a mounting structure for the teeth. The mandible consists of a horseshoe-shaped horizontal portion and two perpendicular portions called rami (ramus singular). Each ramus is provided with a condyloid process consisting of two portions the condyle and its supporting structure the neck. The condyle is located at the top of the ramus adjacent to the mandibular notch.
The condyle provides a surface for articulation with the articular meniscus of the temporo-mandibular joint. The top of the condyle consists of a convex portion that fits into the concave surface of the glenoid fossa of the temporal bone. The articular meniscus is located between these two surfaces. The condyle, articular meniscus and the mandibular fossa essentially act as a pivot point or hinge for the jaw as it moves up and down.
Due to accident or disease, the condyle may have to be replaced by a prosthetic device. Such a device is currently marketed by Vitek, Inc. of Houston, Texas. The Vitek prosthetic condyle is coated with Proplast, a material to encourage tissue ingrowth. Proplast is a registered trademark of Vitek, Inc. and is covered by U.S. Pat. Nos. 3,992,725 and 4,129,470. The underlying prosthetic itself is formed of a cast surgical cobalt-chromium-molybdenum alloy. The head and neck of the prosthetic are curved to facilitate placement.
The Vitek prosthetic condyle has been used in conjunction with a prosthetic glenoid fossa as disclosed in Kent et al, Temporomandibular Joint Condylar Prosthesis: A Ten Year Report, Journal of Oral and Maxillofacial Surgery, Vol. 41, Number 4, April 1983, pp. 245-254.